This gemstone has a gorgeous glittering appearance (known as aventurescence) and is also called Oligoclase, Aventurine Feldspar and Heliote. Sunstone has many sought after attributes, but its aventuresence is the most striking. This is usually caused by either Haematite or Goethite inclusions; but in the Sunstone from Oregon in the USA, this phenomenon owes its appearance to copper inclusions. Although its colour is normally a reddish brown, it has also been discovered in green, grey, and yellow.
The gem has been set in jewellery for thousands of years and is steeped in history and folklore. The Vikings were said to have used the gem as a navigational aid, whilst early American settlers ground the gem and used it in medicine.
Sunstone is a member of the Feldspar family and is closely related to Labradorite. As it is normally opaque or translucent the gem is often cabochon cut; on rare occasions it can be found transparent.
The gem registers 6 to 6.5 on the Mohs scale and can be found in Norway, Canada, India and the USA.